Why are the leaves falling off of my replanted citrus tree?

We uplifted and moved a meyer lemon tree 20yrs old aprox to a different house outdoors. We have been watering everyday for the last 6 days. It looked good the first few days but now there is a little wind and all the leaves are blowing off!! they are not yellowing or anything, just falling off the branches. This tree is very important to our family as it was part of my father in laws orchards and he ped 1 yr ago. The property was sold and the family uprooted and distributed his original 7 trees. Is this normal? Am I overwatering it? Could it be shock? Tree is about 6-7' tall with a canopy girth of about 5-6'. We brought a large bag of its original soil and mixed it with our yard soil and repanted it with this mix...also - we put 2 bags of topsoil over this mixture as a final layer. I live in Ca, it is about 76 degrees during the day and 50's at night. Tree is replanted in an area that gets sun about half the day.